UMD compatible

• Can now specify standard iFrame attributes and CSS [#269]
• Hopefully Fix iOS scroll issue [#77]

Bug fixes

• Changed close icon to a . Be sure to use current CSS files too. [#260]
• Improved focus handling [#259]

Tweak auto binding to work with persist and remove limitation on filter

Fixed namespace option.

Features

• New setting: loading (default is '') is shown initially while content loads. The lightbox also has a class '.featherlight-loading' while content is loading.
• New content-filter "iframe" to generate an iframe with the given URL.
  Options iframeWidth, iframeMinWidth, etc. or their corresponding data attributes
  are used as CSS when present.

Changes

• Basic error handling for images that won't load

Features

• New callback: onResize called for new content and when the window is resized.
• onResize is used to automatically resize images if needed.

Changes

• current() now returns null if no lightbox is currently opened
• now avoids memory leaks
• onKeyDown() renamed onKeyUp()